Growth Response of Bacteria to Extracellular Products of Bloom Algae

Abstract

The growth response of native bacteria isolated from Maizuru Bay to extracellular organic carbon (EOC) of Asterionella glacialis (Bacillariophyceae) and Chattonella marina (Rhaphidophyceae) was examined. A. glacialis EOC selectively stimulated and inhibited the bacterial growth. Growth of a dominant strain Pseudomonas 022 during the bloom of A. glacialis was strongly stimulated by A. glacialis EOC, but Vibrios strains growth were not. Psudomonas 022 utilized selectively not only dissolved free amino acid (DFAA) but also dissolved combined amino acid (DCAA) in the algal EOC. It is suggested that bacteria change the concentration and composition of dissolved amino acids in the bloom period.